This year’s Atlantic hurricane season has already proven to be active and deadly. Powerful hurricanes such as Harvey, Irma and Maria are also providing a testing ground for new tools that scientists hope will save lives by improving forecasts in various ways, from narrowing a storm’s future path to capturing swift changes in the intensity of storm winds.

To the residents of Donora, Pa., a mill town in a crook of the Monongahela River, the daily haze from nearby zinc and steel plants was the price of keeping their families fed. But on October 27, 1948, the city awoke to an unusually sooty sky, even for Donora. The next day, the high school quarterbacks couldn’t see their teammates well enough to complete a single pass.

An alga species that grows on glaciers gives the snow a crimson hue, which increases the amount of sunlight that the snow soaks up and makes it melt faster, new measurements confirm. On Alaska’s Harding Icefield, these microbes are responsible for about a sixth of the snowmelt in algae-tinged areas, researchers report September 18 in Nature...

If the animals are desperate enough to bask like some cold, sluggish turtle, it’s because they’ve got the chills. Robyn Hetem, an ecophysiologist, has the body temperature data to prove it — collected from late 2012 into 2013, the hottest summer the arid Kalahari region in South Africa had seen in more than 30 years.

There’s no signpost to mark it, but about 3,000 meters underwater off the southeast coast of South America, a stream of deep water from the Atlantic Ocean spills into the Southern Ocean. Now new maps reveal in 3-D how the path of that water, called the North Atlantic Deep Water, spirals southeastward and up toward the surface around Antarctica.

Long-term changes in temperature and precipitation are making some rivers flood days, weeks or even months earlier than they did 50 years ago, and pushing flooding in other areas much later, researchers report August 11 in Science. Those changes could impact people, wildlife and farms near rivers.

India and Pakistan are no strangers to extreme temperatures. In 2015, two heat waves killed more than 3,500 people there. But by the end of the century, new climate simulations suggest, extreme heat and humidity could put hundreds of millions at risk of death.

Published online August 2 in Science Advances, the simulations show fairly specifically where future heat waves will be most...

A couple of weeks ago, an article in New York magazine laid out a horrific scenario of global warming. The photo at the top summed up the tone: A fossilized human skull, jaw gaping beneath aviator sunglasses, hovered over a caption warning that people could be “cooked to death from both inside and out” in a hotter climate.

As if air travel weren’t annoying enough, new research suggests that global warming will force planes to carry fewer passengers to get off the ground. While a little more legroom might sound good, it could make flying more expensive.

Researchers examined the impact of rising temperatures on five types of commercial planes flying out of 19 of the world’s busiest airports. In the coming...

As if air travel weren’t annoying enough, new research suggests that global warming could force planes to carry fewer passengers to get off the ground. While a little more legroom might sound good, it could make flying more expensive.

Researchers examined the impact of rising temperatures on five types of commercial planes flying out of 19 of the world’s busiest airports. In the coming...